Booster tube



April 13, 1954 WQRKMAN 2,675,503

BOOSTER TUBE Filed May 21, 1953 INVENTOR.

lie/7r y Workman Patented Apr. 13, 1954 UNITED STATES PATENT OFFICE BOOSTER TUBE Henry Workman, Teaneck, N. J.

Application May 21, 1953, Serial No. 356,447

This invention relates to improvements in socalled booster tubes for use in television receivers and specifically it relates to an improvement involving the use of a pair of resistors of a certain temperature characteristic in the plate leads of a full Wave mercury arc rectifier tube such as type 83 or similar.

I have found that in many localities the voltage drop on the electric power lines is such that television receivers designed for the standard voltage will not give satisfactory reception.

Quite often dark bands will appear on the receiving tube and the picture may appear compressed either horizontally or vertically, due to the reduced voltage on the power supply. I find that these difiiculties can be eliminated by the use of booster resistors in series with the plates in a mercury arc rectifier tube, which I substitute instead of the regular rectifier tube supplied with the receiver. By substituting the mercury arc rectifier tube having two resistors with negative temperature coefficient, one in each of its plate leads, instead of the regular rectifier tube which usually comes with the receiver, I attain a multiple action including a choke action which protects the filter condensers and I also obtain a higher voltage which compensates for the voltage drop in the power line.

An important object of my invention is to provide a booster tube of a lower impedance but having a pair of negative coefiicient resistors in its plate leads, thus providing a high impedance when cold and dropping down to the desired impedance when hot.

Another object of my invention is to provide a booster tube having a negative temperature coeificient characteristic which will act as a choke and only gradually increase the voltage when the set is first turned on, thereby protecting the filter condensers and tubes from burning out due to inruSh current.

Other objects and advantages of my invention will be apparent in the course of the following description.

In the accompanying drawing, forming a part of this specification, in which like numerals designate like parts throughout the same,

Figure 1 represents an elevation of a mercury rectifier tube with an adapter socket embodying my invention,

Figure 2 represents a section taken along the line 2-2 in Figure 1,

Figure 3 represents an enlarged elevation of the internal plate connection with a negative 3 Claims. (Cl. 315-58) temperature cocificient resistor connected in same,

Figure 4 shows a difierent type of resistor placed in the plate lead similarly as shown in Figure 3, and,

Figure 5 shows a circuit diagram embodying my invention.

In the drawings, where for the purpose of illustration, is shown a preferred embodiment of my invention, the numeral [0 designates a standard mercury arc full wave rectifier tube such as the No. 83. Tube Ill has been supplied with an adapter base i l which has the standard connector prongs i2, same as the rectifier tube which is to be replaced in the television receiver. The adapter base II is fastened to the regular base 13 of the tube It) by means of the tubular member Id which has transverse holes l5 for ventilation purposes. In the interior of the adapter base I l are connected a pair of resistors I6. These are connected in series with the plate leads of the tube and are located between the regular base of the tube [0 and the prongs I2 of the adapter base I l.

The resistors I6 are of the negative temperature coefficient type and may have a resistance of from 275 to 300 ohms when cold. When heated by the current, as well as by the heat from the tube, this resistance falls down to about 50 ohms. The nominal impedance of the type 83 mercury arc rectifier tube is about 50 ohms. The series resistor thus will give the tube an impedance of about 350 ohms when cold and about ohms when hot. This 100 ohm hot impedance is still lower than the normal impedance of the usual rectifier tube used in TV sets, which may run from 100 ohms up.

The tube may also, of course, be supplied with the two series resistors built in the tube such as indicated in Figures 3 and 4. In Figure 3 is shown how the plate I1 is connected to one end of the resistor I6 and with the other end of said resistor connected to the external lead [8. In Figure 4 the resistor It has been replaced by a ribbon of negative temperature coefficient is which is welded directly into the plate leads. It is also, of course, possible to make the plate leads themselves out of a suitable negative coefiicient material which would eliminate additional resistors.

The operation of my invention is as follows:

The operation may best be understood by studying the circuit diagram shown in Figure 5. Resistor 16 having negative temperature coeificients are connected into the plate leads of tube l0 which is being supplied by the transacvacoa former 20. My booster tube is here inserted instead of the regular rectifier tube which comes with the television receiver and which feeds the power supply M in the usual fashion. As explained supra, the impedance of the mercury arc rectifier tube which I substitute is only 50 ohms by itself. If used alone this would give too much voltage too suddenly and would quickly burn out filter condensers as well as tubes and other components in the receiver. I, therefore, connect the two resistors 16 in series with the plates of the tube l and inasmuch as these resistors are from 275 to 300 ohms when cold the inrush current is greatly reduced because of the cold impedance of from 325 to 350 ohms. This cold impedance, therefore, acts as a choke to reduce the inrush current when the set is turned on. After these resistors heat up, however, their resistance is reduced to about 50 ohms and the total impedance of the tube is thus about 100 ohms which is still lower than the impedance of the original rectifier tube. The substituted mercury arc tube wil1 therefore, now give a somewhat higher voltage to the power supply which will compensate for the voltage drop in the power lines. The slow build-up of the full load voltage due to the heating up of the resistors will also lengthen the life of the mercury arc rectifier tube. The full voltage is not obtained until about 2 minutes after the set is turned on.

It is to be understood that the form of my invention herewith shown and described is to be taken as a preferred example of the same and that variations in the shape, size and arrangement of parts may be resorted to, without departing from the spirit of my invention or the scope of the subjoined claims.

Having thus described my invention, I claim:

1. A booster tube combination comprising a full wave rectifier tube having a pair of negative temperature coeflicient resistors connected in series with its plate leads.

2. A booster tube combination comprising a full wave mercury arc rectifier tube, an adapter socket fastened to the regular sockets of said tube, said socket having a set of standard connector prongs, and a pair of negative temperature 00- eflicient resistors connected in series with the plate leads of said tube inside of said adapter socket.

3. A booster tube combination comprising a. mercury arc rectifier tube, said mercury arc rectifier tube having its plates mounted upon negative temperature coefiicient resistor elements which are eilectively connected in series with said plates.

References Cited in the file of this patent UNITED STATES PATENTS Number Name Date 1,653,881 Snook Dec. 27, 1927 1,78 ,643 Garrett Dec. 2, 1930 1,802,950 Krahl Apr. 28 1931 1,872,560 Breisky Aug. 16, 1932 1,935,723 Lems Nov. 21, 1933 2,001,498 Meyer et a1. May 14, 1935 2,505,993 Rogers May 2, 1950 

